Cellular resistance to alkylating agents is probably a multifactorial event including several detoxification pathways. In cell lines, the principal cellular nonprotein thiol glutathione (GSH) reacts with several cytotoxic agents by conjugation reaction catalysed by Glutathione-S-transferases (GST). Circumvention of GSH-mediated resistance may thus be achieved by blocking of GSTs. EA has been shown to inhibit GSTs and to enhance chemosensitivity to alkylating agents in cell lines.